Evaluating the in-situ effectiveness of indoor environment guidelines on occupant satisfaction

Post occupancy evaluation (POE) studies typically use a combination of occupant questionnaires and physical measurements of various aspects of the indoor environment to assess building performance. These physical measurements are often compared against published reference limits to evaluate compliance and satisfactory performance. This study investigates whether indoor environment conditions compatible with published indoor environment quality (IEQ) standards and guidelines are predictive of occupant satisfaction. Data used in this study were collected as part of two large building evaluation field studies conducted in the past eight years. Occupant questionnaire and physical measurement data from 11 office buildings across North America were used (N=194). Inputs for the analyses were demographic factors and workstation characteristics, as well as aspects of the measured physical indoor environment. Outcome variables were various measures of environmental satisfaction (i.e. lighting, acoustics/privacy, and ventilation/temperature). The results of this study suggest that occupants had higher satisfaction with lighting when measured desktop illuminance levels were within IESNA RP-1-12 (2012) recommendations. Measured sound levels and thermal conditions within reference limits did not correlate to higher occupant satisfaction in their respective categories

Validation of the use of high dynamic range images and displays in lighting research

Bu çalışmanın amacı, Yüksek Dinamik Ölçekli (YDÖ) görüntüleme tekniğinin kullanıldığı YDÖ monitörlerin aydınlatma mühendisliği problemlerinin çözümünde kullanılabileceğini göstermektedir. Bu makalede sunulan ilk deney, YDÖ monitörde görüntülenen YDÖ fotoğrafların, LCD ekranda görüntülenen (tek pozlamadan oluşan) geleneksel fotoğraflardan daha gerçekçi olduğu hipoteziyle tasarlanmıştır. Altı adet hacmin detaylı parıltı ölçümleri noktasal ölçüm yapabilen bir parıltı ölçer ve parıltı kamerası kullanılarak yapıldıktan sonra, bu parıltı değerleri YDÖ ekrana yansıtılmıştır. Deney sonuçları YDÖ fotoğraf tekniği ile üretilen fotoğrafların YDÖ ekrandaki göruntülerinin, LCD ekranda görüntülenen tek pozlamadan oluşan fotoğraflardan daha gerçekçi algılandığını göstermiştir. Çalışmanın ikinci bölümünde, YDÖ görüntüleme tekniğinden faydalanılarak bir açık plan ofisteki aydınlatma kalitesi incelenmiştir. Bu çalışmada, görüntü karakteristikleri (ortalama parıltı, parıltı dağılımı ve doğal ışığı hacme alan pencere büyüklüğü) ile hacmin aydınlatma kalitesi arasındaki bağıntı incelenmiştir. Çalışmanın sonuçları, YDÖ ekranda sergilenen YDÖ fotoğrafların özellikle doğal ışık içeren görüntülerde aydınlatma kalitesi analizi yapmak amacıyla gerçek hacim yerine kullanılabileceğini göstermektedir. Henüz inşa edilmemiş binaların grafik simulasyonlarının, gerçek hacimde sağlanması öngörülen parıltı değerleriyle YDÖ ekranda görüntülenmesi, aydınlatma projesine ilişkin karar aşamasında faydalı olacaktır. YDÖ teknolojisi kullanılarak elde edilen sonuçlar literatürdeki çalışmalarla tutarlı olması, YDÖ teknolojisinin aydınlatma mühendisliği problemlerinin çözümünde kullanılmasına ilişkin güveni arttırmaktadır. Anahtar Kelimeler: Aydınlatma tasarımı, Yüksek Dinamik Ölçekli fotoğraflama tekniği, Yüksek Dinamik Ölçekli monitör, aydınlatma kalitesi, ofis aydınlatması.The main goal of this study is to show that a High Dynamic Range (HDR) display can be used in the study of lighting engineering problems, and as a tool in the lighting design process to enhance communications between lighting designers and their clients. Printed photographs, renderings or images displayed on conventional Cathode-Ray Tube (CRT) or Liquid-Crystal Display (LCD) monitors do not represent the spaces in realistic luminances. Calibrated HDR images contain luminance information from the real space, but current LCD monitors cannot present luminances as high as the luminances encountered in the real world. Therefore, these sources do not provide enough information to make accurate judgements of light and shade in the lighting design process. The HDR display used in this study could display luminances up to 4000 cd/m2 and overcame these problems. This research shows that the HDR method may be used as a surrogate for experiencing a real space to investigate lighting engineering problems both for research and the design process. The first experiment was designed to investigate the hypothesis that HDR images on an HDR screen would be perceived as more realistic than conventional images displayed on conventional LCD displays. Extensive luminance measurements were conducted using a spot luminance meter and a luminance camera to facilitate accurate reproduction of real space luminances of six scenes (corridor, gym, mezzanine, lobby, open-plan office, staircase) on the HDR display. Thirty-nine participants viewed six scenes in three modes: the real scenes (observing real spaces in the building), single exposure photographs of the scenes shown in conventional mode (screen resolution and luminance of HDR display adjusted to that of a conventional LCD display), and the HDR photographs shown in HDR mode (capable of luminances as high as 4000 cd/m2 and 216 distinct luminance levels). Half of the participants visited the real spaces first, and the other half saw the digital images first. For each presentation (real and digital images), participants rated what they saw on four semantic differential scales: dim - bright; non-uniform - uniform; unpleasant - pleasant; glaring - not glaring. Participants then viewed the six digital image pairs again, and recorded whether the HDR or conventional image was more realistic. This experiment demonstrated that HDR images presented on an HDR display are rated as significantly more realistic than conventional computer images. The second experiment demonstrated the use of HDR images as a research tool. The experiment focused on the relationship between scene characteristics (average luminance, luminance variability and view size) and space appearance judgements. Twenty-one scenes were created, each scene being the view from an interior cubicle across one cubicle to the exterior wall. The scenes varied in terms of the cubicle panels, window blind setting, and presence or absence of a neighbour in the adjacent cubicle. Extensive luminance measurements were conducted. Sets of bracketed images were taken for each of the 21 scenes, and then these images were combined into HDR images using the software Photosphere. The calibrated HDR images were shown on an HDR display at realistic luminances to 43 participants. The participants rated each scene on 8 scales. The average ratings for each image were plotted against the average luminance, luminance variability and relative view size for that image. The second experiment of the dissertation supported the hypothesis that as panel height in an open office gets lower, ratings for satisfaction with lighting increase, and ratings for privacy decrease. As the view size increased, ratings for satisfaction with lighting and amount of view increased. Regarding satisfaction with privacy, Hybrid (one fabric and one glass stack-on on the second panel) performed as well as Standing Privacy (two fabric stack-ons on the second panel), and regarding satisfaction with view and satisfaction with lighting, Hybrid performed better than Standing Privacy.The results imply that HDR displays may be successfully deployed in the lighting research projects. Both experiments show that people can respond to HDR images in the same way as they would respond to the real space. The results of both experiments are consistent with what is already known from studies of images and in real spaces, which adds confidence to the use of HDR display. Keywords: Lighting design, High Dynamic Range images, High Dynamic Range display, real space luminance matching, open-plan office lighting, lighting quality.

​Rapid response to experimental warming of a microbial community inhabiting High Arctic patterned ground soil

The influence of climate change on microbial communities inhabiting the sparsely vegetated patterned ground soils that are widespread across the High Arctic is poorly understood. Here, in a four-year experiment on Svalbard, we warmed patterned ground soil with open top chambers and biannually irrigated the soil to predict the responses of its microbial community to rising temperatures and precipitation. A 1 °C rise in summertime soil temperature caused 44% and 78% increases in CO2 efflux and CH4 consumption, respectively, and a 32% increase in the frequency of bacterial 16S ribosomal RNA genes. Bacterial alpha diversity was unaffected by the treatments, but, of the 40 most frequent bacterial taxa, warming caused 44–45% reductions in the relative abundances of a Sphingomonas sp. and Ferruginibacter sp. and 33–91% increases in those of a Phenylobacterium sp. and a member of the Acetobacteraceae. Warming did not influence the frequency of fungal internal transcribed spacer 2 copies, and irrigation had no effects on the measured variables. Our study suggests rapid changes to the activities and abundances of microbes, and particularly bacteria, in High Arctic patterned ground soils as they warm. At current rates of soil warming on Svalbard (0.8 °C per decade), we anticipate that similar effects to those reported here will manifest themselves in the natural environment by approximately the mid 2030s

The genomes of two key bumblebee species with primitive eusocial organization

Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats. Results: We report the high quality draft genome sequences of Bombus terrestris and Bombus impatiens, two ecologically dominant bumblebees and widely utilized study species. Comparing these new genomes to those of the highly eusocial honeybee Apis mellifera and other Hymenoptera, we identify deeply conserved similarities, as well as novelties key to the biology of these organisms. Some honeybee genome features thought to underpin advanced eusociality are also present in bumblebees, indicating an earlier evolution in the bee lineage. Xenobiotic detoxification and immune genes are similarly depauperate in bumblebees and honeybees, and multiple categories of genes linked to social organization, including development and behavior, show high conservation. Key differences identified include a bias in bumblebee chemoreception towards gustation from olfaction, and striking differences in microRNAs, potentially responsible for gene regulation underlying social and other traits. Conclusions: These two bumblebee genomes provide a foundation for post-genomic research on these key pollinators and insect societies. Overall, gene repertoires suggest that the route to advanced eusociality in bees was mediated by many small changes in many genes and processes, and not by notable expansion or depauperation

A novel palaeoaltimetry proxy based on spore and pollen wall chemistry

Understanding the uplift history and the evolution of high altitude plateaux is of major interest to a wide range of geoscientists and has implications for many disparate fields. Currently the majority of palaeoaltimetry proxies are based on detecting a physical change in climate in response to uplift, making the relationship between uplift and climate difficult to decipher. Furthermore, current palaeoaltimetry proxies have a low degree of precision with errors typically greater than 1 km. This makes the calculation of uplift histories and the identification of the mechanisms responsible for uplift difficult to determine. Here we report on advances in both instrumentation and our understanding of the biogeochemical structure of sporopollenin that are leading to the establishment of a new proxy to track changes in the flux of UV-B radiation over geological time. The UV-B proxy is based on quantifying changes in the concentration of UV-B absorbing compounds (UACs) found in the spores and pollen grains of land plants, with the relative abundances of UACs increasing on exposure to elevated UV-B radiation. Given the physical relationship between altitude and UV-B radiation we suggest that the analysis of sporopollenin chemistry, specifically changes in the concentration of UACs, may offer the basis for the first climate independent palaeoaltimetry proxy. Owing to the ubiquity of spores and pollen in the fossil record our proposed proxy has the potential to enable the reconstruction of the uplift history of high altitude plateaux at unprecedented levels of fidelity, both spatially and temporally

The effect of utility time-varying pricing and load control strategies on residential summer peak electricity use: A review

Peak demand for electricity in North America is expected to grow, challenging electrical utilities to supply this demand in a cost-effective, reliable manner. Therefore, there is growing interest in strategies to reduce peak demand by eliminating electricity use, or shifting it to non-peak times. This strategy is commonly called "demand response". In households, common strategies are time-varying pricing, which charge more for energy use on peak, or direct load control, which allows utilities to curtail certain loads during high demand periods. We reviewed recent North American studies of these strategies. The data suggest that the most effective strategy is a critical peak price (CPP) program with enabling technology to automatically curtail loads on event days. There is little evidence that this causes substantial hardship for occupants, particularly if they have input into which loads are controlled and how, and have an override option. In such cases, a peak load reduction of at least 30% is a reasonable expectation. It might be possible to attain such load reductions without enabling technology by focusing on household types more likely to respond, and providing them with excellent support. A simple time-of-use (TOU) program can only expect to realise on-peak reductions of 5%.Demand response Load shedding